A light valve-based projector, which uses a light valve (a light modulating device) as an image generating device and projects light from a light source that has been modulated by such light valve onto a screen using a lens, and a CRT-based projector, which uses a display apparatus that emits light with high luminance such as a CRT as an image generating device and projects an image displayed on the display apparatus onto a screen using a lens, are known. Typical examples of a light modulating device are a liquid crystal panel and a DMD (Digital Mirror Device or Digital Micro Device). A DMD includes a plurality of elements that form an image by changing the direction of reflection of light.
Japanese Laid-Open Patent Publication No. 2004-212729 discloses a projection lens for use in a projector that is effectively composed of five lenses which, in order from the screen side to the image plane side, are a first lens made up of a single lens with negative refractive power, a second lens made up of a single lens with positive refractive power, a third lens with overall negative refractive power made up of a thirty-first lens with negative refractive power and a thirty-second lens with positive refractive power, and a fourth lens made up of a single lens with positive refractive power. Such projection lens is formed so as to be substantially telecentric toward the image plane side, and the surface on the image plane side of the first lens and the surface on the image plane side of the thirty-second lens are formed as aspherical surfaces.